Align stack pointer on kernel proper entry to 16-byte. Eliminate dead-lock in frame allocator on OOM. Formatting.

kernel/boot.S

@@ -41,8 +41,11 @@ stack_top:
 start:
     /* Setup our stack */
     mov $stack_top, %esp
-    pushl %esp
 
+    /* Make sure our stack is 16-byte aligned */
+    and $-16, %esp
+
+    pushl %esp
     pushl %eax /* Multiboot header magic */
     pushl %ebx /* Multiboot header pointer */
 

kernel/cpu/gdt.c

@@ -74,7 +74,7 @@ void gdt_install(void) {
 }
 
 static void write_tss(int32_t num, uint16_t ss0, uint32_t esp0) {
-	tss_entry_t *tss = &gdt.tss;
+	tss_entry_t * tss = &gdt.tss;
 	uintptr_t base = (uintptr_t)tss;
 	uintptr_t limit = base + sizeof *tss;
 

kernel/cpu/idt.c

@@ -44,7 +44,7 @@ void idt_set_gate(uint8_t num, idt_gate_t base, uint16_t sel, uint8_t flags) {
 }
 
 void idt_install(void) {
-	idt_pointer_t *idtp = &idt.pointer;
+	idt_pointer_t * idtp = &idt.pointer;
 	idtp->limit = sizeof idt.entries - 1;
 	idtp->base = (uintptr_t)&ENTRY(0);
 	memset(&ENTRY(0), 0, sizeof idt.entries);

kernel/cpu/irq.c

@@ -81,7 +81,7 @@ void int_enable(void) {
 
 /* Interrupt Requests */
 #define IRQ_CHAIN_SIZE  16
-#define IRQ_CHAIN_DEPTH	4
+#define IRQ_CHAIN_DEPTH 4
 
 static void (*irqs[IRQ_CHAIN_SIZE])(void);
 static irq_handler_chain_t irq_routines[IRQ_CHAIN_SIZE * IRQ_CHAIN_DEPTH] = { NULL };

kernel/include/pipe.h

@@ -14,8 +14,6 @@ typedef struct _pipe_device {
 	size_t read_ptr;
 	size_t size;
 	size_t refcount;
-	//uint8_t volatile lock_read;
-	//uint8_t volatile lock_write;
 	volatile int lock_read[2];
 	volatile int lock_write[2];
 	list_t * wait_queue_readers;

kernel/include/task.h

@@ -3,7 +3,6 @@
 
 #include <types.h>
 
-
 typedef struct page {
 	unsigned int present:1;
 	unsigned int rw:1;

kernel/mem/mem.c

@@ -60,6 +60,7 @@ kmalloc_real(
 				spin_lock(frame_alloc_lock);
 				uint32_t index = first_n_frames((size + 0xFFF) / 0x1000);
 				if (index == 0xFFFFFFFF) {
+					spin_unlock(frame_alloc_lock);
 					return 0;
 				}
 				for (unsigned int i = 0; i < (size + 0xFFF) / 0x1000; ++i) {